US3585586A
Expired / Lapsed
US
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Facsimile transmission system
Assignee: Datamax Inc
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Filing: 1968-08-28
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Granted: 1971-06-15
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Expires: 1988-08-28
Abstract
Abstract A facsimile transmission system includes a transmitter wherein copy is scanned and a two-value digitized signal is generated. The signal is redundantly encoded and the encoded signal is converted into parallel form and time interleaved. The output of the interleaver is used to generate an analog pulse width modulated signal which is provided to a receiver over a transmission channel. At the receiver the analog signal is converted into a digital form, passed through a complimentary interleaver and back into serial form, and is decoded to detect and correct errors in the transmission before being provided to a facsimile receiver.
Inventors
- 👤 Samuel T Harmon
- 👤 David E Klingler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:12
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/41; H04N1/411; H04N1/413; H04N1/4135
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
247 words
A facsimile reproduction system including, in combination: a facsimile transmitter operative to scan a sheet of original copy to generate an electrical signal having a characteristic which is a function of the graphic content of the point on the copy being instantaneously scanned; means for accepting said electrical signal and for sampling it at regular intervals to provide a serial digital signal wherein each digit has a characteristic which is a function of said characteristic of the electrical signal at a particular instant; means for forming a plural parallel digit word wherein at least certain of the digits represents one of the digits of said serial signal; means, under control of said parallel signals for generating a transmission signal which has a characteristic which may assume any one of a series of states, the states being related to the words in such a way that words representative of adjacent states differ from one another by no more than one digit; a transmission channel operative to receive said transmission signal; a converter operative to receive the transmission signal from the transmission channel at a location remote from the transmitter and to reconstruct the serial digital signal from it; and a facsimile receiver having an output member operative to scan a sheet in synchronism with the transmitter scan, the condition of said output member being controlled by the instantaneous state of said reconstructed serial digital signal to operate on the sheet to create a facsimile of the original copy.
Claim 2
Dependent Claim
247 words
A facsimile reproduction system including, in combination: a facsimile transmitter operative to scan a sheet of original copy to generate an electrical signal having a characteristic which is a function of the graphic content of the point on the copy being instantaneously scanned; means for accepting said electrical signal and for sampling it at regular intervals to provide a serial digital signal wherein each digit has a characteristic which is a function of said characteristic of the electrical signal at a particular instant; means for forming a plural parallel digit word wherein at least certain of the digits represents one of the digits of said serial signal; means, under control of said parallel signals for generating a transmission signal which has a characteristic which may assume any one of a series of states, the states being related to the words in such a way that words representative of adjacent states differ from one another by no more than one digit; a transmission channel operative to receive said transmission signal; a converter operative to receive the transmission signal from the transmission channel at a location remote from the transmitter and to reconstruct the serial digital signal from it; and a facsimile receiver having an output member operative to scan a sheet in synchronism with the transmitter scan, the condition of said output member being controlled by the instantaneous state of said reconstructed serial digital signal to operate on the sheet to create a facsimile of the original copy.
Claim 3
Dependent Claim
44 words
The facsimile reproduction system of claim 1 wherein said characteristic of said serial digital signal may assume one n state, wherein said plural parallel digit word contains m digits and wherein said characteristic of the transmission signal may assume any one of nm states.
Claim 4
Dependent Claim
30 words
The facsimile reproduction system of claim 2 wherein said serial digital signal is a binary signal, and said characteristic of the transmission signal may assume any one of 2m states.
Claim 5
Dependent Claim
97 words
The facsimile reproduction system of claim 1 wherein means are provided for passing each of the digits of the plural parallel digit word through one of a plurality of first delays of varying length prior to providing the word to the transmission channel; and means are provided for passing each of the digits of the reconstructed serial digital signal through one of a plurality of second delays before providing it to the facsimile receiver, the sum of the first and second delays through which a particular digit and its equivalent are passed being equal for all digits.
Claim 6
Dependent Claim
61 words
The facsimile reproduction system of claim 1 wherein certain of the digits of the parallel word have states which are a function of the states of a plurality of digits in the serial digital signal and the reconstructed serial digital signal is decoded into the form of the serial digital signal by detectiNg and correcting errors introduced into the transmission channel.
Claim 7
Dependent Claim
56 words
The facsimile reproduction system of claim 5 wherein each of the digits of the serial digital signal is passed through one of a plurality of first delays, and each of the digits of the reconstructed serial digital signal is passed through one of a plurality of second differing delays before being provided to the facsimile receiver.
Claim 8
Dependent Claim
31 words
The facsimile reproduction system of claim 6 wherein the state of the characteristic of the transmission signal is related to the plural digit parallel word in accordance with the Gray code.
Claim 9
Dependent Claim
94 words
The facsimile reproduction system of claim 1 wherein said characteristic of the transmission signal which may assume any one of a series of states constitutes the widths of pulses, one of which is formed under control of each plural digit parallel word, and wherein the widths of said pulses may assume any one of a series of states, the states being related to the parallel words in such a way that words representative of pulses which are immediately adjacent to one another in width differ from one another by no more than one digit.
Claim 10
Dependent Claim
48 words
The facsimile reproduction system of claim 8 wherein said means for generating a transmission signal includes a counter chain, a two state element, and means for changing the state of the two state element upon the occurrence of a selected condition of the states of the counter chain.
Claim 11
Dependent Claim
208 words
A facsimile reproduction system including, in combination: a facsimile transmitter operative to scan a sheet of original copy to generate an electrical signal having a characteristic which is a function of the graphic content of the point on the copy being instantaneously scanned; means for accepting said electrical signal and for sampling it at regular intervals to provide a serial digital signal wherein each digit has a characteristic which is a function of said characteristic of the electrical signal; an encoder for generating a redundant signal having a greater number of digits than the serial digital signal, each digit of the redundant signal being the function of the condition of one or more of the digits of the serial digital signal; a transmission channel operative to receive said redundant signal; a decoder operative to receive the redundant signal from the transmission channel at a location remote from the transmitter and to reconstruct the serial digital signal from it; and a facsimile receiver having an output member operative to scan a sheet in synchronism with the transmitter scan, the condition of said output member being controlled by the instantaneous state of said reconstructed serial digital signal to operate on the sheet to create a facsimile of the original copy.
Claim 12
Dependent Claim
208 words
A facsimile reproduction system including, in combination: a facsimile transmitter operative to scan a sheet of original copy to generate an electrical signal having a characteristic which is a function of the graphic content of the point on the copy being instantaneously scanned; means for accepting said electrical signal and for sampling it at regular intervals to provide a serial digital signal wherein each digit has a characteristic which is a function of said characteristic of the electrical signal; an encoder for generating a redundant signal having a greater number of digits than the serial digital signal, each digit of the redundant signal being the function of the condition of one or more of the digits of the serial digital signal; a transmission channel operative to receive said redundant signal; a decoder operative to receive the redundant signal from the transmission channel at a location remote from the transmitter and to reconstruct the serial digital signal from it; and a facsimile receiver having an output member operative to scan a sheet in synchronism with the transmitter scan, the condition of said output member being controlled by the instantaneous state of said reconstructed serial digital signal to operate on the sheet to create a facsimile of the original copy.
Claim 13
Dependent Claim
64 words
The facsimile reproduction system of claim 10 wherein the decoder operates to reconstruct the serial digital signal from the redundant signal by detecting errors in the redundant signal on the basis of inconsistencies between various of the digits of the redundant signal, and corrects at least certain of the errors so detected by reconstructing the serial digital signal so as to eliminate such inconsistencies.
Claim 14
Dependent Claim
23 words
The facsimile reproduction system of claim 11 wherein the encoder is of the convolutional type and the decoder is of the sequential type.
Claim 15
Dependent Claim
39 words
The facsimile reproduction system of claim 10 wherein the redundant signal contains all of the digits of the serial digital signal plus additional digits which are each a function of a plurality of digits in the serial digital signal.
Claim 16
Dependent Claim
70 words
The facsimile reproduction system of claim 13 wherein the decoder separates those digits which are a function of single digits in the serial-digital signal from the redundant signal and employs them to generate internal check digits which are compared with those digits of the redundant signal which are a function of a plurality of the digits in the serial digital signal, in order to detect errors in the redundant signal.
Claim 17
Dependent Claim
27 words
The facsimile reproduction system of Claim 11 wherein means are provided for disabling the decoder upon the detection of certain classes of errors in the redundant signal.
Claim 18
Dependent Claim
68 words
The facsimile reproduction system of claim 10 wherein the digits of the redundant signal are arranged into parallel code words containing m digits, each digit having one of n states, means is provided for encoding such words into a transmission signal having nm possible states before provision to the transmission channel, and means is provided to decode such transmission signal into the redundant signal at the receiver location.
Claim 19
Dependent Claim
30 words
The facsimile reproduction system of claim 16 wherein adjacent states of the transmission signal are functions of code words which differ from one another by no more than one digit.
Claim 20
Dependent Claim
32 words
The facsimile reproduction system of claim 16 wherein means are provided for scrambling the digits of the redundant signal at the transmitter and regrouping them in their original orientation at the receiver.
Claim 21
Dependent Claim
250 words
A facsimile reproduction system including, in combination: a facsimile transmitter operative to scan a sheet of original copy to generate an electrical signal having a characteristic which is a function of the graphic content of the point on the copy being instantaneously scanned; means for accepting said electrical signal and for sampling it at regular intervals to provide a digital signal wherein each digit has a characteristic which is a function of said characteristic of the electrical signal at a particular instance; delay means operative to receive said digital signal and to delay each various of its digits by one of a first plurality of differing delays so as to form an interleaved signal at the output of the delay means; a transmission channel operative to receive said interleaved signal; a complementary delay unit operative to receive said delayed signal from the transmission channel at a location remote from the transmitter and to pass each of the sequentially appearing digits of the interleaved signal through one of a plurality of second delay units of varying length, the sum of the delays provided to a particular digit at the receiver end and its equivalent at the transmitter end being the same for all of the digits; and a facsimile receiver having an output member operative to scan a sheet in synchronism with the transmitter scan, the condition of said output member being controlled by the instantaneous state of the serial digital signal appearing at the outputs of the complementary delay unit.
Claim 22
Dependent Claim
250 words
A facsimile reproduction system including, in combination: a facsimile transmitter operative to scan a sheet of original copy to generate an electrical signal having a characteristic which is a function of the graphic content of the point on the copy being instantaneously scanned; means for accepting said electrical signal and for sampling it at regular intervals to provide a digital signal wherein each digit has a characteristic which is a function of said characteristic of the electrical signal at a particular instance; delay means operative to receive said digital signal and to delay each various of its digits by one of a first plurality of differing delays so as to form an interleaved signal at the output of the delay means; a transmission channel operative to receive said interleaved signal; a complementary delay unit operative to receive said delayed signal from the transmission channel at a location remote from the transmitter and to pass each of the sequentially appearing digits of the interleaved signal through one of a plurality of second delay units of varying length, the sum of the delays provided to a particular digit at the receiver end and its equivalent at the transmitter end being the same for all of the digits; and a facsimile receiver having an output member operative to scan a sheet in synchronism with the transmitter scan, the condition of said output member being controlled by the instantaneous state of the serial digital signal appearing at the outputs of the complementary delay unit.
Claim 23
Dependent Claim
50 words
The facsimile reproduction system of claim 19 wherein the serial digital signal is arranged into a plurality of parallel digit words prior to being input to the delay means and is rearranged to serial form at the output of the complementary delay means at the receiver end of the system.
Claim 24
Dependent Claim
75 words
The facsimile reproduction system of claim 20 wherein the parallel output of the delay means is used to generate a transmission signal having one of nm states wherein n is the number of states which a digit of the parallel digit word may have and m is the number of digits in the parallel word and such signal having nm states is decoded at the receiver end before being input to the complementary delay unit.
Claim 25
Dependent Claim
210 words
A facsimile reproduction system including, in combination: a facsimile transmitter operative to scan a sheet of original copy to generate an electrical signal having a characteristic which is a function of the graphic content of the point on the copy being instantaneously scanned; means for accepting said electrical signal and for sampling it at regular intervals to provide a digital signal wherein each digit has a characteristic which is a function of said characteristic of the electrical signal at a particular instance; delay means operative to receive said digital signal and to provide an output signal wherein the digits of the digital signal are arranged in a time sequence which differs from that of said digital signal; a transmissiOn channel operative to receive the output of the delay means; a complementary delay unit operative to receive the signal from the transmission channel at a location remote from the transmitter and to operate upon such signal so as to effectively rearrange the digits thereof into their original sequence; and a facsimile receiver having an output member operative to scan a sheet in synchronism with the transmitter scan, the condition of said output member being controlled by the instantaneous state of the signal appearing at the output of the complementary delay unit.
Claim 26
Dependent Claim
210 words
A facsimile reproduction system including, in combination: a facsimile transmitter operative to scan a sheet of original copy to generate an electrical signal having a characteristic which is a function of the graphic content of the point on the copy being instantaneously scanned; means for accepting said electrical signal and for sampling it at regular intervals to provide a digital signal wherein each digit has a characteristic which is a function of said characteristic of the electrical signal at a particular instance; delay means operative to receive said digital signal and to provide an output signal wherein the digits of the digital signal are arranged in a time sequence which differs from that of said digital signal; a transmissiOn channel operative to receive the output of the delay means; a complementary delay unit operative to receive the signal from the transmission channel at a location remote from the transmitter and to operate upon such signal so as to effectively rearrange the digits thereof into their original sequence; and a facsimile receiver having an output member operative to scan a sheet in synchronism with the transmitter scan, the condition of said output member being controlled by the instantaneous state of the signal appearing at the output of the complementary delay unit.
Claim 27
Dependent Claim
44 words
The facsimile reproduction system of claim 22 wherein the serial digital signal is encoded in redundant form prior to provision to the delay means and is decoded at the output of the complementary delay means to detect and correct errors resulting from the transmission.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |